It is known to arrange road toll facilities for automatic fee debiting, see for example U.S. Pat. No. 4,104,630 and U.S. Pat. No. 4,303,904.
Such systems to which the present invention refers, provide that the majority of vehicles that pass the toll facility, are provided with a receiver-transmitter unit for radiowaves. Usually microwaves are understood. The road toll facility comprises an arrangement by which communication by radiowaves can take place with passing vehicles. This arrangement comprises a transmitter and receiver, a transceiver, for the radiowaves by means of which equipment payment and debiting operations can be carried out for the passing vehicles provided with said reciever and transmitter unit, which unit usually has the form of a transponder. For this technique compare U.S. Pat. No. 4,075,632 and U.S. Pat. No. 4,242,661 for example.
However, it may occur, that the toll facility is passed by vehicles which are not provided with any receiver and transmitter equipment and therefore cannot be identified by means of the radiowaves. For identification of such vehicles, if these attempt at passing the toll facility without paying toll, the toll arrangement is provided with camera devices for image registration of the number plates of the vehicles in question for search and post-debiting.
The most advanced system for road tolls of this kind is adapted to a great flow of traffic in free formation. In such an arrangement it will be possible to for the vehicle to travel a certain distance from the time when a registration has been possible to carry out of whether the vehicle is identifiable through microwaves or not and until the recording operation regarding the number plate has been concluded.
During this displacement a separation must be maintained between such vehicles for which search and post-debiting shall take place, and such for which payment has been secured by means of the radio communication. This requires additionally that the toll arrangement is provided with an equipment for positioning detection also when the vehicles travel in free flow without determined lanes.